Apparatus for testing oil in lubricating systems



J. A. WILSON April 26, 1955 APPARATUS FOR TESTING OIL IN LUBRICATINGSYSTEMS Filed Aug. 18, 1951 James CZ .Uflsorz {Srzverzbor IMMW mu :t/: SS 7 W y mijn; HZ 4 A w I l6 |/|,./.l.ldH|l|Y|l..N\| 9 I I 9 3 m 5: 5; 7.,1 .r l

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United States Patent APPARATUS FOR TESTING OIL IN LUBRICATING SYSTEMSJames A. Wilson, Linden, N. J., assignor to Esso Research andEngineering Company, a corporation of Delaware Application August 18,1951, Serial No. 242,569

8 Claims. (Cl. 73-61) The present invention relates to apparatus fortesting oil in lubricating systems, and particularly in systems fromwhich a relatively small stream of oil may be continuously diverted orwithdrawn over an extended period of time. The invention is especiallyapplicable for testing the quality, degree of contamination, or extentof eterioration, etc., of crank case lubricating oil in internalcombustion engines. Such systems require periodic checking and arealmost universally used in automotive vehicles. Hence they constitute amost important class of oil or lubricating systems but it will beunderstood that the present invention is applicable also to othersystems and in fact to almost any system where oil in a closed zone isused over an extended period so that it is desirable to check itsquality at frequent intervals.

In the oil industry, continuous efforts are made by variousmanufacturers and refiners of lubricating oils to learn more about thetype, rate, and extent of deterioration of lubricating oil products.Since crank case lubricants form a most important class of lubricantsbecause of their extensive use, much of the time and expense involved instudying lubricant problems is con- Other types of lubricants areimportant, also, such as those used in enclosed gear lubricant systems,lubricants for steam turbines, and oils for hydraulic oil systems,automotive transmission systems, transformer and other electricalinsulation oil systems, etc. An object of the present invention is tomake available an improved and simplified sampling system for theperiodic or continuous evaluation of oils and related products of any ofthe types mentioned above.

A further object of the present invention is to make it possible to takeover an extended period of time a continuous sample of an oil from alubricating system such as an internal combustion engine crankcase tod..- termine the sludge-forming tendencies and other elements ofdeterioration within such oil while the oil is still in service.

A further and specific object is to provide an apparatus which can beinserted into the crankcase lubricating system of a conventionalautomotive vehicle through the measuring stick opening which is commonlyprovided in such systems.

Other and further objects will appear more fully as this descriptionproceeds. Reference Will, therefore, be made next to the attacheddrawings forming a part of this specification wherein specific physicalembodiments of the invention are illustrated in detail. Referring to thedrawings,

Figure l is an elevational view with parts shown in section of anapparatus embodying the invention;

Figure 2 is an enlarged cross-sectional detail of the apparatus ofFigure 1 taken substantially along the line 2-2 of Figure 1 and lookingin the direction of the arrows;

Figure 3 is a fragmentary view with parts broken away of an apparatuscorresponding to that of Figure 1, but differing in certain details.

Referring first to Figure l the apparatus of the invention is shown ascomprising a unit for Withdrawing oil from and recirculating it to thecrankcase of an internal combustion engine of a standard automotivetype. In this figure the crankcase wall 11 is shown fragmentarily,terminating in its upper portion in a cylinder wall 13, said cylinderwall being jacketed as at 15 to provide suitable cooling as isconventional in internal combustion engines, particularly automotiveengines.

2,766,905 Patented Apr. 26, 1955 "ice At an upper portion indicated at17 the crankcase Wall is provided with an opening 19 and a conventionalmeasuring stick or dip stick which is used by service station personneland others to ascertain the oil level within the crank case. The oillevel is indicated by line 21 and obviously it may vary from time totime as the oil supply is increased or diminished.

The apparatus representing the improvement of the present inventioncomprises a slender tube assembly composed of an outer tubular member 23of such diameter that it can be readily inserted in the measuring stickopening 19. Arranged more or less concentrically within the outertubular member 23 is a smaller tube 25. These tubes 23 and 25 are ofsuch relative sizes that the slender inner tube 25 is spaced from theinner wall of the outer tube 23 to leave an annular passage throughwhich oil may flow.

The lower portion of the outer tube 23 is provided with a foraminated orperforated portion to make a fine screen which will remove solidparticles and other foreign matter from the lubricating oil which flowsthrough the screen openings. This screen element 27 may be an integralpart of the tube 23 or it may be detachable therefrom by flanged orthreaded connections indicated generally at 29.

At its upper end the tube assembly has a flange member 31 suitablysecured to the upper end of the outer tube 23 and a circulating pump 33is attached to the enlarged flange element 31. The pump may be of anysuitable construction; for example it may be of either centrifugal orgear type. It is so arranged and connected to the tube assembly that oilis withdrawn from the crankcase through one of the tubes and returnedthrough the other to provide circulation which will cause the oil to bescreened through the element 27. The amount and rate of the depositsupon the screen 27, and the type of such deposits will indicate the typeand character of the deterioration taking place in the oil in thecrankcase.

Although the arrangement may be revised if desired, as shown in Figure 1oil is drawn into the test apparatus through the annular space 35 whichseparates the inner tube from the outer tube; see also Figure 2. Thisoil passes into the central part of the pump 33 and is returned througha peripherally located outlet port into the extended end 37 of the innertube 25. Since the lower end of the annular passage is closed asindicated at 39, Figure 1, see also Figure 2, the oil must be drawn intothe outer tube through the openings in the screen element 27. The massand character of the solid materials which collect on the screen may beevaluated by weighing and by other obvious methods.

The circulating pump, which is not shown in detail in Figure 1 but isindicated within the housing 33, is driven by any suitable prime mover,preferably by a six volt motor 45 which may be directly connected to thepump through a drive shaft 47. This motor is driven electrically by thebattery of the automotive vehicle to which it is connected through leads47' and 49. One of these leads, shown at 49, is preferably connected inseries with an automatic control device such as the temperatureresponsive switch 51 mounted in an appropriate manner on the jacketedcylinder wall. The arrangement is such that the contacts 53 of a switchare open normally. When the engine reaches operating temperature, forexample to 200 F. or so, the contacts close to energize the motor 45.The motor drives the circulating pump and circulates a continuous streamof oil, withdrawing it from the crankcase and pumping it back into thecrankcase, this oil being screened and foreign matter contained thereinbeing collected on the outer surface of the screen 27. A manual switch(not shown) may be provided for turning the motor 45 on or off withoutregard to the thermostat control. The latter may of course be omitted ifdesired.

It will be understood of course that the system might be operated inreverse, oil being drawn in through the inner tube and forced outthrough the foraminated screen member 27. In the latter case theimpurities, solids, etc., would collect inside the screen member 27. Insuch a case it would be particularly desirable to have the screen memberreadily detachable from the outer tube element 23 as indicated at 29,previously mentioned.

Another modification is shown in Figure 3 wherein both the inner andouter tube members 25 and 23 respectively are provided with screenelements 27' and 28'. In this case, as illustrated, a centrifugal typepump is mounted on top of the tube assembly as indicated at 33', theimpeller 34 being shown fragmentarily. In this arrangement also theinner tube 25 is connected to the central or inlet opening of the pumpas indicated at 61, the outer tube 23 being connected to the peripheralport as shown at 63. In the arrangement shown the oil is drawn into thetest apparatus through the perforated screen element 23 attached to theinner tube 25 and is forced out through the screen 27'. The mesh orfineness of the respective screens may be chosen so as to collect thelarger solid particles on screen 28 and the finer particles of foreignmatter inside the screen 27. In this case it is desirable to make bothscreen elements detachable from their respective tubes although this isnot altogether necessary.

It will be understood that the operation of the apparatus of Figure 3,as in the case of the apparatus previously described, may be reversed sothat oil is drawn into the test apparatus through screen 27 and returnedthrough the inner tube with its screen element 28. Both tubes, ofcourse, are closed at their lower ends as indicated at 65 and 67respectively.

It will be understood also that a similar apparatus may be used in otheroil systems as in transmission and diiferential units of automotivevehicles, electrical transformers, oil systems and steam turbines, andother analogous installations. The convenience of being able to insertthe apparatus through an existing opening which is standard inautomotive equipment plus the facility of driving the test unit fromstandard battery circuits of automotive vehicles makes the unitparticularly adaptable for testing crankcase oils and the like inautomotive vehicles. A similar procedure may be adopted for testing thequality of oils in automatic transmissions, gear cases, diiierentialhousings and the like.

It will be understood that various modifications and variations may bemade within the spirit of the present invention and within the scope ofthe appended claims. The invention embodies apparatus for testing oils,the operation of which involves continuously withdrawing a stream of oilfrom an operating lubricating system without interrupting the ordinaryoperations and without necessitating taking down of equipment or removalof mechanical parts.

What is claimed is:

1. In apparatus of the character described for testing crankcaselubricating oil in service in a closed oil crankcase having a narrowmeasuring stick opening, a removable depending slender tubular assemblyincluding an outer tube adapted to be inserted into said opening andcontaining a smaller concentrically mounted tube spaced from the innerwalls thereof to provide an annular passage, a circulating pump attachedto the upper end of said assembly and arranged to draw a sample streamof oil upwardly through one of said tubes and return it downwardlythrough the other, means for operating said pump, and a screen formed atthe end of one of said tubes and being of sufiicient fineness to retainthereon relatively solid particles from the stream whereby the relativeparticle content of said oil may be measured.

2. Combination according to claim 1 wherein the screen forms a portionof one of the tubes.

3. In apparatus for continuously withdrawing over an extended period asample stream of oil from a closed oil crankcase having a narrowmeasuring stick opening, a slender tube assembly comprising an outertube adapted to be inserted into said opening and a concentric innertube of smaller diameter annularly spaced from the inner wall thereof, acirculating pump connected between said tubes to draw oil from saidcrankcase through one tube and return it through the other, means foroperating said pump, and screen means provided in at least one of saidtubes for removing foreign matter from said oil.

4. Apparatus according to claim 3 wherein said screen means is providedin the outer tube.

5. Apparatus according to claim 3 wherein said screen means is providedin the inner tube.

6. In apparatus for testing crankcase oil in an internal combustionengine having a measuring stick opening, the combination of a slendertube assembly comprising a slender outer tube adapted to be inserted insaid measuring stick opening and having a foraminated screen structurein its lower portion and an inner tube annularly spaced from the innerwall of said first mentioned tube, a pump for drawing oil from saidcrankcase through one of said tubes and through said screen structureand returning it through the other tube, means for operating said pump,and temperature responsive means for controlling said operating means topump oil only when said engine is at operating temperature.

7. Apparatus according to claim 6 wherein a foraminated screen elementis provided in both tubes.

8. Apparatus according to claim 6 wherein the foraminated screen portionis detachable for cleaning.

References Cited in the file of this patent UNITED STATES PATENTS1,649,198 Shikles et al. Nov. 15, 1927 1,836,269 McKenzie Dec. 15, 19312,145,304 Hill Jan. 31, 1939 2,331,119 Gouldbourn et a1. Oct. 5, 19432,448,157 Schneider Aug. 31, 1948

1. IN APPARATUS OF THE CHARACTER DESCRIBED FOR TESTING CRANKCASELUBRICATING OIL IN SERVICE IN A CLOSED OIL CRANKCASE HAVING A NARROWMEASURING STICK OPENING, A REMOVABLE DEPENDING SLENDER TUBULAR ASSEMBLYINCLUDING AN OUTER TUBE ADAPTED TO BE INSERTED INTO SAID OPENING ANDCONTAINING A SMALLER CONCENTRICALLY MOUNTED TUBE SPACED FROM THE INNERWALLS THEREOF TO PROVIDE AN ANNULAR PASSAGE, A CIRCULATING PUMPATTACCHED TO THE UPPER END OF SAID